11 - Haemopoiesis

Question 1

Outline the process of haemopoeisis with growth factors used.

Answer 1

Stem Cells –> Myeloid or Lymphoblasts

Question 2

Where does haematopoiesis take place?

Answer 2

Question 3

What are monocytes and granulocytes?

Answer 3

Monocytes - Precursor of macrophages

Granulocytes - White blood cells containing granules

Question 4

What is the structure and function of erythrocytes?

Answer 4

• Biconcave carry oxygen
• Live 120 days and then removed by liver or spleen. Iron recycled, protoporphyrin broken down to bilirubin and excreted in faeces
• Peritublar endothelial cells detect hypoxia and release erythropoeitin

Question 5

Where are the following released from:

• Erythropoietin?
• Thromobpoietin?
• G-CSF?
• Interleukins?

Answer 5

1. Kidney
2. Liver, Kidney, Skeletal muscle cells, stromal cells of bone marrow
3. Macrophages and immune cells and endothelium
4. Activated T-cells and mast cells

Question 6

What are leucocytes?

Answer 6

Nucleated white blood cells

Question 7

What is the structure and function of a neutrophil?

Answer 7

Question 8

What is the structure and function of eosinophils?

Answer 8

Question 9

What is the structure and function of Basophils?

Answer 9

Question 10

What is the structure and function of monocytes?

Answer 10

Question 11

Distinguish what white blood cells look like under the microscope

Answer 11

Question 12

What are the different types of T-lymphocyes?

Answer 12

Helper:

• CD4 on surface
• Recognise other immune cells by HLA Class II
• Stimulate cytotoxic t-cells
• Aid humoral immunity (convert b cells to plasma cells)

Cytotoxic:

- Recognise and kill virally infected cells by stimulating apoptosis

NK Cells:

• Stimulate virally infected cells or cancer cells to undergo apoptosis by releasing granozymes and perforin

Question 13

What is the structure and function of B-cells?

Answer 13

Antibodies on surface, convert to plasma cells and secret immunoglobulins

Question 14

What is the structure of platelets?

Answer 14

Originate from megakaryocytes

Contain granules:

• Alpha-Granules - Fibrinogen, Factors and other large molecules
• Dense Granules - ADP and Calcium

Question 15

Briefly outline how platelets form clots.

Answer 15

1. Injury
2. Vessel contracts due to serotonin release
3. Platelet adhesion to endothelial wall
4. Platelet aggregation with other platelets
5. Platelets provide phospholipid surface for binding of clotting factors

Question 16

What is a cytokine?

Answer 16

Growth factor, e.g IL6 or G-CSF that stimulates chemotaxis and phagocytosis

Question 17

How could you overcome an issue with a low RBC count?

Answer 17

Inject EPO

Question 18

What order do white blood cells arrive at the scene of infection?

Answer 18

Never Let Monkeys Eat Bananas

Question 19

What is thalassaemia?

Answer 19

Any hereditary haemolytic disorder caused by faulty haemoglobin synthesis

Question 21

What is:

• Haemolytic Anaemia
• Aplastic Anaemia
• Haemophillia

Answer 21

1. Removal of RBC before 120 day. High reticulocyte count. Treat with blood transfusion or splenectomy
2. Haemopoietic stem cells damaged. Bone marrow transplant. Low reticulocyte count
3. Lack of clotting factors so blood cannot clot

Question 22

What is chronic myeloid leukemia?

Answer 22

Myeloid precursor mutated so cells cannot mature into mature WBC’s. Too many immature WBC’s released and don’t work properly, accumulate in organs and stop them working properly

Question 23

What are the words associated with high and low blood cell counts?

Answer 23

High:

• Thrombocythemia
• Leukemia
• Polycythemia (RBC)

Low:

• Anaemia
• Leucopenia
• Thrombocytopenia

PANCYTOPENIA = LOW EVERYTHING

Question 24

If a primary haemotological disorder is suspected what do you do?

Answer 24

• Take bone marrow transplant using trephine
• Superior posterior iliac crest
• Can then stimulate bone marrow to release stem cells and use stem cells for bone marrow transplant

Question 25

What does a reiticulocyte look like?

Answer 25